1. Field of the Invention
The present invention relates to a method of initializing and establishing links, and more particularly, to a method of initializing and establishing links in a multi-mode mobile terminal.
2. Discussion of the Related Art
FIG. 1 is a diagram showing a Protocol Stack Architecture according to IEEE 802.16. As shown in FIG. 1, conversion or mapping of the data, received from the outside communication network via the CS Service Access Point (SAP), to MAC Service Data Unit (SDU), received by a MAC Common Part Sublayer (CPS) via the MAC SAP can take place at a Service-Specific Convergence Sublayer (CS). Here, the SDUs of the outside communication network are classified and assigned to corresponding MAC Service Flow Identifier (SFID) or Connection Identifier (CID). For a diverse protocol interface, provisions related to a multiple CS are provided. The internal format of the CS payload is considered a unique characteristic of the CS. Moreover, the MAC CPS is not required to analyze or comprehend the format of any information received after the CS payload.
The MAC CPS provides features such as system access, allocation of broadband width, establishing access, and access management. Moreover, the MAC CPS receives data, classified by a specific MAC access method, from various CS via the MAC SAP. Furthermore, the data is transmitted through the PHY layer while Quality of Service (QoS) is applied to the scheduling feature.
The PHY control and statistical data from between the MAC CPS and the PHY is transmitted via the PHY SAP. In the definition of the PHY, there are various provisions and is appropriate in each specific frequency range and application.
FIG. 2 illustrates the protocol stack architecture of IEEE 802.11, and FIG. 3 illustrates the protocol stack architecture of 3rd Generation Partnership Project (3GPP).
In IEEE 802.21, discussions are under way to establish an international standard for a Media Independent Handover (MIH) between heterogeneous networks. One of the objects of the international standard is to provide seamless handover and service continuity to enhance user experience of mobile devices. As a basic requirement, there are a MIH function, an event trigger, a Command Service (CS) and an Information Service (IS).
A mobile terminal is a multi modal which supports at least one interface type, and the interface types can be any one of the following. The interface types include a wire-line type similar an Ethernet of IEEE 802.3, a wireless interfaces based on IEEE 802.xx (e.g., 802.11, 802.15, 802.16), and an interface defined by a cellular standard organization (e.g., 3rd Generation Partnership Program (3GPP), 3rd Generation Partnership Program 2 (3GPP2)).
The MIH is defined between the IEEE 802 series interfaces or between the IEEE802 series interfaces and non-IEEE 802 series interfaces (e.g., 3GPP, 3GPP2). Furthermore, the MIH has to be supported by upper layer mobile support protocol such as a Mobile Internet Protocol (Mobile IP) and a Session Initiation Protocol (SIP) in order to provide seamless handover and uninterrupted service.
FIG. 4 illustrates a general MIH reference model used to support MIH function. The SAP for supporting the MIH function is as follows.
MIH_MGMT_SAP defines the interface between the MIH function stack and the management plane. MIH_MGMT_SAP can be used to send the MIH messages to peer MIH entities. The messages near the management frame can be sent without authentication. MIH_MGMT_SAP indicates the primitives used by Media Independent Event Services, Media Independent Command Services, and Media Independent Information Services.
MIH_SME_SAP defines the interface between the MIH function stack and a Station Management Entity (SME) of IEEE 802.11 or between MIH function stack and a Network Control and Management System (NCMS) of IEEE 802.16. Furthermore, MIH_SME_SAP can be same as MIH_MGMT_SAP.
MIH_USER_SAP defines the interfaces for communicating with the layers above the upper layers (e.g., IP layer-Layer 3).
MIH_MAC_SAP defines the interface between the MIH and the MAC of other interfaces. The other interfaces include, for example, IEEE 802.11, IEEE 802.16, 3GPP, and 3GPP2. The interfaces indicated by MIH_MAC_SAP are used to transmit between peer entities. Here, no new interfaces and primitives need to be defined for MIH_MAC_SAP. However, the interfaces indicated by MIN_MAC_SAP can be used by the peer MIH entities to transmit the payloads near the MIH protocol.
MIH_PHY_SAP defines the interface between the MIH and the PHY layer of other interfaces (e.g., IEEE 802.11, IEEE 802.16, 3GPP, and 3GPP2). Here, the MIH uses the MACs of the corresponding interface to communicate via the PHY of the corresponding interface. There is no need to define new interfaces or primitives for MIH_PHY_SAP.
A Layer SAP (LSAP) defines the interface between the MIH and a Lower Link Control (LLC) of other interfaces. The MIH establishes connection and communicates with the peer LLC entities. Thereafter, the MIH uses the LLC interface directly to establish data path for transmitting MSDUs via other links. Here, there is no need to define new interfaces or primitives for LSAP.
MIH_RRC_SAP defines the interface between the MIH function and the interfaces between a Radio Resource Control (RRC) of other interfaces.
The MIH function is placed below the IP layer. The MIH function facilitates the handover handling process by using the input values from Layer 2 such as trigger event information and information of other networks. Moreover, the MIH Function can include input values (e.g., user policy and configuration) which can affect the handover procedure. In addition, general interfaces (e.g., the Mobile IP and the SIP) are defined between Layer 3 entities and the MIH Function. These interfaces provide information associated with Layer 1 (i.e., PHY Layer) and Layer 2 (i.e., MAC Layer) as well as mobility management. The MIH acquires information on lower layer and the network with the aid of the ES and the IS.
Furthermore, in the upper layer, the mobile terminal should include the MIH function for monitoring and controlling the status of other links. FIG. 5 illustrates a mobile terminal having the MIH function and a functional entity and transmission protocol of a network. In FIG. 5, the dotted lines represent services such as a primitive and the event trigger.
FIG. 6 illustrates a configuration of an IEEE 802.16 system in a protocol stack considering the MIH. This model can be applied to both the mobile terminal and the network. However, because a multi-mode mobile subscriber station and a multi-stack mobile subscriber station should be taken into consideration, a mobile subscriber station should include the configuration shown in FIG. 6.
FIG. 7 illustrates a configuration of an IEEE 802.11 system in a protocol stack considering the MIH. This model can be applied to both the mobile terminal and the network. However, because a multi-stack mobile subscriber station of multi-mode should be taken into consideration, a mobile subscriber station should include the configuration shown in FIG. 7.
FIG. 8 illustrates a configuration of a 3GPP system in a protocol stack considering the MIH. This model can be applied to both the mobile terminal and the network. However, because a multi-stack mobile subscriber station of multi-mode should be taken into consideration, a mobile subscriber station should include the configuration shown in FIG. 8.
According to the conventional art, there is no way to initialize and establish control link in a multi-mode mobile terminal having at least two interface types associated with the wired or wireless schemes. In particular, if placed in the MIH stack, there is no way to establish link for operating the mobile terminal and accessing the network and to control each interface of the multi-mode mobile terminal. As such, there are delays in operating the mobile terminal and accessing the network. Moreover, since power of the multi-mode mobile terminal could not be managed, power consumption by the multi-mode mobile terminal was excessive.